Ratchet clutch mechanism



owls, 1938. f N. BLISS :TAL 2,133,777

RA'I'CHET CLUTCH MECHANI SM Filed March 4, 1937 zl we/wtm H42? VEY N52158 EDWARD VVJLD Patented "on. ia-193s PATENT OFFICE.

BATCHET CLUTCH MECHANISM Harvey N. Bliss, Windsor, and Edward Wild,

Hartford, Conn., assignors to Veeden-Root Incorporated, Hartford, Conn.,a corporation of Connecticut Application March 4,

Claims.

This invention relates to a ratchet clutch mechanism which flndsparticular application in a counter unit of the type having a numeralwheel, a drive member or gear, and a connec- 5 tion therebetween in theform of a' ratchet de vice whereby the drive gear and numeral wheel maybe driven as a unit during a registering operation and the numeral wheelmay be reset to a starting position'without transmitting ro- 4 tation tothe drive gear during the resetting counter unit of the characterdescribed an ini proved arrangement of pawls which is very simple andeconomical, which will permit a ready assembly, wherein the extent ofmovement of the pawls is effectively limited, and wherein breakage ofthe springs associated with the pawls is reduced to a minimum.

It is a further object of this invention provide a counter device havinga small numher of parts and including a driving unit and a driven unitwhich may be quickly and easily assembled without the use of tools.

A still further object of the invention-is to provide an improvedarrangement for a counter unit having the above and other advantages andwherein the numeral wheel and driving member are automatically andproperly located'relativ to one another. I I

Other objects will be in part obvious and in Part pointed out more indetail hereinafter.

The invention accordingly consists in the features of construction,combination of elements and arrangement of parts which will beexemplifled in the construction hereafter set forth as and the scope ofthe application of which will 1937, Serial No. 1zs,sss

Fig. 4 is a side elevationsimilar to Fig. l but with the drive memberremoved:

Fig. 5 is a sectional view through the ratchet wheel forming part of thecounter unit; and

Fig, 6 is a side elevation showing one of the pawls. In accordance withthe present invention as illustrated, we have provided a numeral wheel'A containing a ratchet wheel l0 rigidly secured thereto or forming apart thereof, and a drive member Ii journalled on a hub of the numeralwheel transmits unidirectional rotation thereto 4 by means of pawls ii.The numeral wheel A is rotatably mounted in cooperative relation withone or more similar numeral wheels on a reset shaft 9 which is normallyheld fixed during a counting operation. This shaft is provided with alongitudinally extending groove 9'. During a resetting operation, theshaft is rotated in the same direction as that in which the counter unitis driven for registration, At this time, the groove. will pick up-'thenose portion of a spring pressed reset pawl pivotally carried by thenumeral wheel causing the numeral wheel to be reset to a' zero or otherstarting position. This resetting movement is independent of the drivingmember in view of the ratchet connection between the drive member andthe numeral wheel. The wheel A is provided with a central hub I! fromwhich extends a disk like web I terminating in a peripheral flange ll.Spaced numerals from 0" to 9 may be provide on the flange in'consecutiverelation in accordance with general practice to register a countingoperation. The numeral wheel A also has an annular cavity ll between hubi5 and flange l1. and the ratchet wheel Iii is supported in this cavitycoaxialLv of wheel A by rivets I9 passing through bosses it extendingfrom web it so that any rotation imparted to. the ratchet wheel willresult in a corresponding'rotation of wheel A, In the present showing,the ratchet wheel it which has a central hole I 0' receiving hub i5, isblanked out from sheet metal and bent to form, providing ratchet teeth28 spaced by notches 2i. These teeth comprise duplicate bent overportions extending substantially at right angles from, and to one sideof, the body portion of the ratchet wheel at its periphery. In order toinsure proper relation between the driving gear and the numeral wheel,each of these teeth are of V shape having a pair of obtusely disposedinterconnected walls 24 and-25, the apexes of the teeth being disposedtowards the the wheel, so that the adjacent walls 28 and 25 of adjacentteeth form the notches 2| in substantiallyv shape. However, the presentshowing is only exemplary of one embodiment of a numeral wheel andratchet wheel assembly, and it will be appreciated that a numeral wheelhaving similarly shaped and similarly located V shaped teeth integrallyformed therewith and within cavity l8 would not deviate from the scopeof our invention.

The outer left-hand end of hub l5, as viewed in Fig. 2, projects beyondthe plane of the edge of flange l1 and terminates in a reduced bearingportion 23 upon which is journalled the diskshaped drive member H which,in the present instance, is illustrated in the form of a gear havinguniformly spaced peripheral teeth M. For the purpose oflioperativelyassociating the drive member or gear II with the numeral wheel,

there is provided a pair of pawls l2 pivotally mounted between theirends on studs 27 carried by. the driving gear. Springs 33 connectedbetween studs 34 on the drive member and hooked ends 35 'on the pawlsnormallyurge the outer or driving ends 36 of the pawls into engagementwith the ratchet teeth. As shown in Fig. 6, the opposite ends of thepawls are offset to facilitate the attachment of springs 33 and toassure the proper engagement of the outer pawl ends with teeth 20. Ithas been found advisable in the assembly of our counter units on a resetshaft to permit a slight amount of end play between the drive member lland the numeral wheel to prevent the binding of parts. As shown in Fig.2, the extent of offset of the outer end of each pawl is such that thepawl cannot spring past the ends of the V-shaped teeth.

The outer .or driving end of each pawl is so constructed and shaped asto cooperate with the adjacent V-shaped teeth in order .to insure aproper driving relation between the drive gear and the numeral wheel andalso to permit tuming of the number wheel and ratchet wheelindependently of the driving gearduring a resetting operation. Moreparticularly, the driving end of each pawl has an end edge l2"' and aside edge 13 disposed relative to one another at substantially the sameangle-as are the walls 24 and 25 of adjacent ratchet teeth so that whenthe parts are in proper driving relation those edges will respectivelyengage said sides of the teeth. The corner l2 between the edges l2" andI3 is curved so as to have a camming action on the teeth which insuresthat the driving end of the pawl will properly ride into a seatedposition within the notch formed by the adjacent walls 24 and 25 ofadjacent teeth and also to permit the pawl to ride out of those notchesduring the resettingoperation. In view of the fact that each tooth 20has its two sloping walls 24 and 25 diverging outwardly from an apex, itwill be appreciated that the camming action of the pawls against theteeth will tend to locate the numeral wheel in predetermined relation tothe drive member with the pawls seated between adjacent teeth, as shownin Fig. 1.

Hence, there will be no tendency for the pawls to frictionally locate onintermediate tooth portions and the numeral wheel will not stop in' anintermediate registering position between two of its numbers eitherduring a counting or a resetting movement.

In accordance with the present invention, there is provided a verysimple and efiective arrangement for mounting the pawls in position andfor mounting the drive gear in the inter-- est of economy and ease ofassembly. To these ends, the studs 21 which are carried by and extendlaterally from the inner. face of gear it have on their outer endsenlarged heads 2'5, and each pawl has a key slot opening 30 having anenlarged portion 30' through which the head is adapted. to be receivedand a smaller portion 30" adapted to closely and rotatably receive theshank of the stud behind the head. Durin assembly, the enlarged portion30 is first passed.

This struckout portion 31 moves into engage ment with the opposite edgesof hole 38 and limits the extent'of pivotal movement of its pawl intoand out of driving position, Hence, springs 33 are economically limitedas to the extent of,

their. resilient movement, and the pawls are maintained at all times injournalled position on their respective studs. Struck out portions 37and holes 38 are preferably so positioned relative to each other thatthe outer ends of the driving pawls are so located that they may beeasily slid into toothed engagement with the ratchet wheel to facilitateassembly of the counter unit without requiring the use of tools.

It is, of course, understood that the drive gear ll may be rotatedeither directly by the driving mechanism or through the usual transferpinion, depending upon whether the unit is the first or a subsequent oneof a series composing the counter assembly.. On the side of the wheelopposite the drive gear II and secured by rivets I9 is the usual lockingdisk 42 having a mutilated or two toothed gear 43 struck out from it andadapted to cooperate with the usual transfer pinion for operating thenext succeeding unit. The transfer mechanism may be similar to thatdisclosed in the patent to Spaunburg No. 2,040,031 issued'May 5, 1936,and needs no further description. It is apparent, of course, that thepositions of the ratchet wheel and pawls may be reversed, the ratchetwheel being secured to the driving member and the pawls being carried bythe numeral wheel, and such an arrangement comes within the scope of theappended claims.

As many changes could be made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained in the above description -or shown in the accompanyingdrawings shall be interpreted as illustrativeand not in a limitingsense.

v It is also to be understood that the language used in the followingclaims is intended'to cover of language, might be said to falltherebetween.

We claim as our invention:

1. In combination, a driven member, a ratchet wheel secured thereto andhaving peripheral, equally spaced apart, laterally extending teeth withnotches therebetween, a driving member rotatable relative to said drivenmember and having an aperture, a pawl pivoted between its ends on saiddriving member eccentrically with respect to the axis of the unit andhaving one end adapted to engage with said teeth, and acoiled springanchored at one end to said driving member and connected at its otherend to the other end of said pawl for urging the driving end of the pawlinto engagement with said teeth, said pawl having a projection extendinglaterally therefrom and projecting into said aperture .ior limiting theextent of movement of said pawl under the influence of said spring.

2. In combination, a driven member, a ratchet wheel secured thereto andhaving spaced laterally extending teeth to one side thereof, a drivingmember rotatable relative to the ratchet wheel,

a stud extending laterally from the driving memher and having a shankportion and a head, a pawl having one end engageable with said teeth,said pawl having an aperture between its ends provided with an enlargedportion for accoms -modating said head and a smaller portion forreceiving saidshank, and a spring between the driving member and theother end of said pawl urging the pawl into toothed engagement andmaintaining said reduced portion in iournalled engagement with the shankportion of the stud.

3. In combination, a driven member, means associated with the drivenmember and having annularly disposed, laterally extending, V-shapedconnected at its other end to the other end of said pawl i'or urging thepawl into tooth engagement, said pawl having 'a laterally extendingprojection between its ends and extending into said aperture forengagement with the sides of the aperture to limit the extent of pawlmovement under influence of said spring.

4. In combination, a driven member, a driving member rotatably supportedadjacent to said driven member, one of said members having a set ofannularly disposed, laterally extending, spaced, V-shaped teeth securedthereto and having their apexes disposed towards the axis of rotation ofsaid member, a stud extending laterally from the other member and havinga shank portion and a head, a pawl having one end engageable with saidteeth and having an aperture between its ends provided with an enlargedportion for accommodating said head and a smaller portion for receivingsaid shank, and resilient means between 20 ing an aperture, a studextending laterally i'rom the driving member and having a shank portionand a head. a pawl having one end engageable with said teeth, saidpawlhaving an aperture be- .tween its ends provided with an enlarged portionfor accommodating said head and a smaller portion for receiving theshank, and a spring between the driving member and-the other end of saidpawl urging the pawl into toothed engagement and maintaining saidreduced portion journalled on the shank, said pawl having a lateralprojection extending into-the aperture of the driving member forlimiting the extent of pawl movement under influence of said spring.

, HARVEY N. BLISS.

EDWARD WILD.

